rust/src/liballoc/tests/str.rs

// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use std::borrow::Cow;
use std::cmp::Ordering::{Equal, Greater, Less};
use std::str::from_utf8;

#[test]
fn test_le() {
    assert!("" <= "");
    assert!("" <= "foo");
    assert!("foo" <= "foo");
    assert!("foo" != "bar");
}

#[test]
fn test_find() {
    assert_eq!("hello".find('l'), Some(2));
    assert_eq!("hello".find(|c:char| c == 'o'), Some(4));
    assert!("hello".find('x').is_none());
    assert!("hello".find(|c:char| c == 'x').is_none());
    assert_eq!("ประเทศไทย中华Việt Nam".find('华'), Some(30));
    assert_eq!("ประเทศไทย中华Việt Nam".find(|c: char| c == '华'), Some(30));
}

#[test]
fn test_rfind() {
    assert_eq!("hello".rfind('l'), Some(3));
    assert_eq!("hello".rfind(|c:char| c == 'o'), Some(4));
    assert!("hello".rfind('x').is_none());
    assert!("hello".rfind(|c:char| c == 'x').is_none());
    assert_eq!("ประเทศไทย中华Việt Nam".rfind('华'), Some(30));
    assert_eq!("ประเทศไทย中华Việt Nam".rfind(|c: char| c == '华'), Some(30));
}

#[test]
fn test_collect() {
    let empty = "";
    let s: String = empty.chars().collect();
    assert_eq!(empty, s);
    let data = "ประเทศไทย中";
    let s: String = data.chars().collect();
    assert_eq!(data, s);
}

#[test]
fn test_into_bytes() {
    let data = String::from("asdf");
    let buf = data.into_bytes();
    assert_eq!(buf, b"asdf");
}

#[test]
fn test_find_str() {
    // byte positions
    assert_eq!("".find(""), Some(0));
    assert!("banana".find("apple pie").is_none());

    let data = "abcabc";
    assert_eq!(data[0..6].find("ab"), Some(0));
    assert_eq!(data[2..6].find("ab"), Some(3 - 2));
    assert!(data[2..4].find("ab").is_none());

    let string = "ประเทศไทย中华Việt Nam";
    let mut data = String::from(string);
    data.push_str(string);
    assert!(data.find("ไท华").is_none());
    assert_eq!(data[0..43].find(""), Some(0));
    assert_eq!(data[6..43].find(""), Some(6 - 6));

    assert_eq!(data[0..43].find("ประ"), Some( 0));
    assert_eq!(data[0..43].find("ทศไ"), Some(12));
    assert_eq!(data[0..43].find("ย中"), Some(24));
    assert_eq!(data[0..43].find("iệt"), Some(34));
    assert_eq!(data[0..43].find("Nam"), Some(40));

    assert_eq!(data[43..86].find("ประ"), Some(43 - 43));
    assert_eq!(data[43..86].find("ทศไ"), Some(55 - 43));
    assert_eq!(data[43..86].find("ย中"), Some(67 - 43));
    assert_eq!(data[43..86].find("iệt"), Some(77 - 43));
    assert_eq!(data[43..86].find("Nam"), Some(83 - 43));

    // find every substring -- assert that it finds it, or an earlier occurrence.
    let string = "Việt Namacbaabcaabaaba";
    for (i, ci) in string.char_indices() {
        let ip = i + ci.len_utf8();
        for j in string[ip..].char_indices()
                             .map(|(i, _)| i)
                             .chain(Some(string.len() - ip))
        {
            let pat = &string[i..ip + j];
            assert!(match string.find(pat) {
                None => false,
                Some(x) => x <= i,
            });
            assert!(match string.rfind(pat) {
                None => false,
                Some(x) => x >= i,
            });
        }
    }
}

fn s(x: &str) -> String { x.to_string() }

macro_rules! test_concat {
    ($expected: expr, $string: expr) => {
        {
            let s: String = $string.concat();
            assert_eq!($expected, s);
        }
    }
}

#[test]
fn test_concat_for_different_types() {
    test_concat!("ab", vec![s("a"), s("b")]);
    test_concat!("ab", vec!["a", "b"]);
}

#[test]
fn test_concat_for_different_lengths() {
    let empty: &[&str] = &[];
    test_concat!("", empty);
    test_concat!("a", ["a"]);
    test_concat!("ab", ["a", "b"]);
    test_concat!("abc", ["", "a", "bc"]);
}

macro_rules! test_join {
    ($expected: expr, $string: expr, $delim: expr) => {
        {
            let s = $string.join($delim);
            assert_eq!($expected, s);
        }
    }
}

#[test]
fn test_join_for_different_types() {
    test_join!("a-b", ["a", "b"], "-");
    let hyphen = "-".to_string();
    test_join!("a-b", [s("a"), s("b")], &*hyphen);
    test_join!("a-b", vec!["a", "b"], &*hyphen);
    test_join!("a-b", &*vec!["a", "b"], "-");
    test_join!("a-b", vec![s("a"), s("b")], "-");
}

#[test]
fn test_join_for_different_lengths() {
    let empty: &[&str] = &[];
    test_join!("", empty, "-");
    test_join!("a", ["a"], "-");
    test_join!("a-b", ["a", "b"], "-");
    test_join!("-a-bc", ["", "a", "bc"], "-");
}

#[test]
fn test_unsafe_slice() {
    assert_eq!("ab", unsafe {"abc".slice_unchecked(0, 2)});
    assert_eq!("bc", unsafe {"abc".slice_unchecked(1, 3)});
    assert_eq!("", unsafe {"abc".slice_unchecked(1, 1)});
    fn a_million_letter_a() -> String {
        let mut i = 0;
        let mut rs = String::new();
        while i < 100000 {
            rs.push_str("aaaaaaaaaa");
            i += 1;
        }
        rs
    }
    fn half_a_million_letter_a() -> String {
        let mut i = 0;
        let mut rs = String::new();
        while i < 100000 {
            rs.push_str("aaaaa");
            i += 1;
        }
        rs
    }
    let letters = a_million_letter_a();
    assert_eq!(half_a_million_letter_a(),
        unsafe { letters.slice_unchecked(0, 500000)});
}

#[test]
fn test_starts_with() {
    assert!("".starts_with(""));
    assert!("abc".starts_with(""));
    assert!("abc".starts_with("a"));
    assert!(!"a".starts_with("abc"));
    assert!(!"".starts_with("abc"));
    assert!(!"ödd".starts_with("-"));
    assert!("ödd".starts_with("öd"));
}

#[test]
fn test_ends_with() {
    assert!("".ends_with(""));
    assert!("abc".ends_with(""));
    assert!("abc".ends_with("c"));
    assert!(!"a".ends_with("abc"));
    assert!(!"".ends_with("abc"));
    assert!(!"ddö".ends_with("-"));
    assert!("ddö".ends_with("dö"));
}

#[test]
fn test_is_empty() {
    assert!("".is_empty());
    assert!(!"a".is_empty());
}

#[test]
fn test_replacen() {
    assert_eq!("".replacen('a', "b", 5), "");
    assert_eq!("acaaa".replacen("a", "b", 3), "bcbba");
    assert_eq!("aaaa".replacen("a", "b", 0), "aaaa");

    let test = "test";
    assert_eq!(" test test ".replacen(test, "toast", 3), " toast toast ");
    assert_eq!(" test test ".replacen(test, "toast", 0), " test test ");
    assert_eq!(" test test ".replacen(test, "", 5), "   ");

    assert_eq!("qwer123zxc789".replacen(char::is_numeric, "", 3), "qwerzxc789");
}

#[test]
fn test_replace() {
    let a = "a";
    assert_eq!("".replace(a, "b"), "");
    assert_eq!("a".replace(a, "b"), "b");
    assert_eq!("ab".replace(a, "b"), "bb");
    let test = "test";
    assert_eq!(" test test ".replace(test, "toast"), " toast toast ");
    assert_eq!(" test test ".replace(test, ""), "   ");
}

#[test]
fn test_replace_2a() {
    let data = "ประเทศไทย中华";
    let repl = "دولة الكويت";

    let a = "ประเ";
    let a2 = "دولة الكويتทศไทย中华";
    assert_eq!(data.replace(a, repl), a2);
}

#[test]
fn test_replace_2b() {
    let data = "ประเทศไทย中华";
    let repl = "دولة الكويت";

    let b = "ะเ";
    let b2 = "ปรدولة الكويتทศไทย中华";
    assert_eq!(data.replace(b, repl), b2);
}

#[test]
fn test_replace_2c() {
    let data = "ประเทศไทย中华";
    let repl = "دولة الكويت";

    let c = "中华";
    let c2 = "ประเทศไทยدولة الكويت";
    assert_eq!(data.replace(c, repl), c2);
}

#[test]
fn test_replace_2d() {
    let data = "ประเทศไทย中华";
    let repl = "دولة الكويت";

    let d = "ไท华";
    assert_eq!(data.replace(d, repl), data);
}

#[test]
fn test_replace_pattern() {
    let data = "abcdαβγδabcdαβγδ";
    assert_eq!(data.replace("dαβ", "😺😺😺"), "abc😺😺😺γδabc😺😺😺γδ");
    assert_eq!(data.replace('γ', "😺😺😺"), "abcdαβ😺😺😺δabcdαβ😺😺😺δ");
    assert_eq!(data.replace(&['a', 'γ'] as &[_], "😺😺😺"), "😺😺😺bcdαβ😺😺😺δ😺😺😺bcdαβ😺😺😺δ");
    assert_eq!(data.replace(|c| c == 'γ', "😺😺😺"), "abcdαβ😺😺😺δabcdαβ😺😺😺δ");
}

mod slice_index {
    // Test a slicing operation **that should succeed,**
    // testing it on all of the indexing methods.
    //
    // DO NOT use this in `should_panic` tests, unless you are testing the macro itself.
    macro_rules! assert_range_eq {
        ($s:expr, $range:expr, $expected:expr)
        => {
            let mut s: String = $s.to_owned();
            let mut expected: String = $expected.to_owned();
            {
                let s: &str = &s;
                let expected: &str = &expected;

                assert_eq!(&s[$range], expected, "(in assertion for: index)");
                assert_eq!(s.get($range), Some(expected), "(in assertion for: get)");
                unsafe {
                    assert_eq!(
                        s.get_unchecked($range), expected,
                        "(in assertion for: get_unchecked)",
                    );
                }
            }
            {
                let s: &mut str = &mut s;
                let expected: &mut str = &mut expected;

                assert_eq!(
                    &mut s[$range], expected,
                    "(in assertion for: index_mut)",
                );
                assert_eq!(
                    s.get_mut($range), Some(&mut expected[..]),
                    "(in assertion for: get_mut)",
                );
                unsafe {
                    assert_eq!(
                        s.get_unchecked_mut($range), expected,
                        "(in assertion for: get_unchecked_mut)",
                    );
                }
            }
        }
    }

    // Make sure the macro can actually detect bugs,
    // because if it can't, then what are we even doing here?
    //
    // (Be aware this only demonstrates the ability to detect bugs
    //  in the FIRST method it calls, as the macro is not designed
    //  to be used in `should_panic`)
    #[test]
    #[should_panic(expected = "out of bounds")]
    fn assert_range_eq_can_fail_by_panic() {
        assert_range_eq!("abc", 0..5, "abc");
    }

    // (Be aware this only demonstrates the ability to detect bugs
    //  in the FIRST method it calls, as the macro is not designed
    //  to be used in `should_panic`)
    #[test]
    #[should_panic(expected = "==")]
    fn assert_range_eq_can_fail_by_inequality() {
        assert_range_eq!("abc", 0..2, "abc");
    }

    // Generates test cases for bad index operations.
    //
    // This generates `should_panic` test cases for Index/IndexMut
    // and `None` test cases for get/get_mut.
    macro_rules! panic_cases {
        ($(
            mod $case_name:ident {
                let DATA = $data:expr;

                // optional:
                //
                // a similar input for which DATA[input] succeeds, and the corresponding
                // output str. This helps validate "critical points" where an input range
                // straddles the boundary between valid and invalid.
                // (such as the input `len..len`, which is just barely valid)
                $(
                    let GOOD_INPUT = $good:expr;
                    let GOOD_OUTPUT = $output:expr;
                )*

                let BAD_INPUT = $bad:expr;
                const EXPECT_MSG = $expect_msg:expr; // must be a literal

                !!generate_tests!!
            }
        )*) => {$(
            mod $case_name {
                #[test]
                fn pass() {
                    let mut v: String = $data.into();

                    $( assert_range_eq!(v, $good, $output); )*

                    {
                        let v: &str = &v;
                        assert_eq!(v.get($bad), None, "(in None assertion for get)");
                    }

                    {
                        let v: &mut str = &mut v;
                        assert_eq!(v.get_mut($bad), None, "(in None assertion for get_mut)");
                    }
                }

                #[test]
                #[should_panic(expected = $expect_msg)]
                fn index_fail() {
                    let v: String = $data.into();
                    let v: &str = &v;
                    let _v = &v[$bad];
                }

                #[test]
                #[should_panic(expected = $expect_msg)]
                fn index_mut_fail() {
                    let mut v: String = $data.into();
                    let v: &mut str = &mut v;
                    let _v = &mut v[$bad];
                }
            }
        )*};
    }

    #[test]
    fn simple_ascii() {
        assert_range_eq!("abc", .., "abc");

        assert_range_eq!("abc", 0..2, "ab");
        assert_range_eq!("abc", 0..=1, "ab");
        assert_range_eq!("abc", ..2, "ab");
        assert_range_eq!("abc", ..=1, "ab");

        assert_range_eq!("abc", 1..3, "bc");
        assert_range_eq!("abc", 1..=2, "bc");
        assert_range_eq!("abc", 1..1, "");
        assert_range_eq!("abc", 1..=0, "");
    }

    #[test]
    fn simple_unicode() {
        // 日本
        assert_range_eq!("\u{65e5}\u{672c}", .., "\u{65e5}\u{672c}");

        assert_range_eq!("\u{65e5}\u{672c}", 0..3, "\u{65e5}");
        assert_range_eq!("\u{65e5}\u{672c}", 0..=2, "\u{65e5}");
        assert_range_eq!("\u{65e5}\u{672c}", ..3, "\u{65e5}");
        assert_range_eq!("\u{65e5}\u{672c}", ..=2, "\u{65e5}");

        assert_range_eq!("\u{65e5}\u{672c}", 3..6, "\u{672c}");
        assert_range_eq!("\u{65e5}\u{672c}", 3..=5, "\u{672c}");
        assert_range_eq!("\u{65e5}\u{672c}", 3.., "\u{672c}");

        let data = "ประเทศไทย中华";
        assert_range_eq!(data, 0..3, "ป");
        assert_range_eq!(data, 3..6, "ร");
        assert_range_eq!(data, 3..3, "");
        assert_range_eq!(data, 30..33, "华");

        /*0: 中
          3: 华
          6: V
          7: i
          8: ệ
         11: t
         12:
         13: N
         14: a
         15: m */
        let ss = "中华Việt Nam";
        assert_range_eq!(ss, 3..6, "华");
        assert_range_eq!(ss, 6..16, "Việt Nam");
        assert_range_eq!(ss, 6..=15, "Việt Nam");
        assert_range_eq!(ss, 6.., "Việt Nam");

        assert_range_eq!(ss, 0..3, "中");
        assert_range_eq!(ss, 3..7, "华V");
        assert_range_eq!(ss, 3..=6, "华V");
        assert_range_eq!(ss, 3..3, "");
        assert_range_eq!(ss, 3..=2, "");
    }

    #[test]
    fn simple_big() {
        fn a_million_letter_x() -> String {
            let mut i = 0;
            let mut rs = String::new();
            while i < 100000 {
                rs.push_str("华华华华华华华华华华");
                i += 1;
            }
            rs
        }
        fn half_a_million_letter_x() -> String {
            let mut i = 0;
            let mut rs = String::new();
            while i < 100000 {
                rs.push_str("华华华华华");
                i += 1;
            }
            rs
        }
        let letters = a_million_letter_x();
        assert_range_eq!(letters, 0..3 * 500000, half_a_million_letter_x());
    }

    #[test]
    #[should_panic]
    fn test_slice_fail() {
        &"中华Việt Nam"[0..2];
    }

    panic_cases! {
        mod rangefrom_len {
            let DATA = "abcdef";

            let GOOD_INPUT = 6..;
            let GOOD_OUTPUT = "";

            let BAD_INPUT = 7..;
            const EXPECT_MSG = "out of bounds";

            !!generate_tests!!
        }

        mod rangeto_len {
            let DATA = "abcdef";

            let GOOD_INPUT = ..6;
            let GOOD_OUTPUT = "abcdef";

            let BAD_INPUT = ..7;
            const EXPECT_MSG = "out of bounds";

            !!generate_tests!!
        }

        mod rangetoinclusive_len {
            let DATA = "abcdef";

            let GOOD_INPUT = ..=5;
            let GOOD_OUTPUT = "abcdef";

            let BAD_INPUT = ..=6;
            const EXPECT_MSG = "out of bounds";

            !!generate_tests!!
        }

        mod range_len_len {
            let DATA = "abcdef";

            let GOOD_INPUT = 6..6;
            let GOOD_OUTPUT = "";

            let BAD_INPUT = 7..7;
            const EXPECT_MSG = "out of bounds";

            !!generate_tests!!
        }

        mod rangeinclusive_len_len {
            let DATA = "abcdef";

            let GOOD_INPUT = 6..=5;
            let GOOD_OUTPUT = "";

            let BAD_INPUT = 7..=6;
            const EXPECT_MSG = "out of bounds";

            !!generate_tests!!
        }
    }

    panic_cases! {
        mod range_neg_width {
            let DATA = "abcdef";

            let GOOD_INPUT = 4..4;
            let GOOD_OUTPUT = "";

            let BAD_INPUT = 4..3;
            const EXPECT_MSG = "begin <= end (4 <= 3)";

            !!generate_tests!!
        }

        mod rangeinclusive_neg_width {
            let DATA = "abcdef";

            let GOOD_INPUT = 4..=3;
            let GOOD_OUTPUT = "";

            let BAD_INPUT = 4..=2;
            const EXPECT_MSG = "begin <= end (4 <= 3)";

            !!generate_tests!!
        }
    }

    mod overflow {
        panic_cases! {

            mod rangeinclusive {
                let DATA = "hello";

                let BAD_INPUT = 1..=usize::max_value();
                const EXPECT_MSG = "maximum usize";

                !!generate_tests!!
            }

            mod rangetoinclusive {
                let DATA = "hello";

                let BAD_INPUT = ..=usize::max_value();
                const EXPECT_MSG = "maximum usize";

                !!generate_tests!!
            }
        }
    }

    mod boundary {
        const DATA: &'static str = "abcαβγ";

        const BAD_START: usize = 4;
        const GOOD_START: usize = 3;
        const BAD_END: usize = 6;
        const GOOD_END: usize = 7;
        const BAD_END_INCL: usize = BAD_END - 1;
        const GOOD_END_INCL: usize = GOOD_END - 1;

        // it is especially important to test all of the different range types here
        // because some of the logic may be duplicated as part of micro-optimizations
        // to dodge unicode boundary checks on half-ranges.
        panic_cases! {
            mod range_1 {
                let DATA = super::DATA;

                let BAD_INPUT = super::BAD_START..super::GOOD_END;
                const EXPECT_MSG =
                    "byte index 4 is not a char boundary; it is inside 'α' (bytes 3..5) of";

                !!generate_tests!!
            }

            mod range_2 {
                let DATA = super::DATA;

                let BAD_INPUT = super::GOOD_START..super::BAD_END;
                const EXPECT_MSG =
                    "byte index 6 is not a char boundary; it is inside 'β' (bytes 5..7) of";

                !!generate_tests!!
            }

            mod rangefrom {
                let DATA = super::DATA;

                let BAD_INPUT = super::BAD_START..;
                const EXPECT_MSG =
                    "byte index 4 is not a char boundary; it is inside 'α' (bytes 3..5) of";

                !!generate_tests!!
            }

            mod rangeto {
                let DATA = super::DATA;

                let BAD_INPUT = ..super::BAD_END;
                const EXPECT_MSG =
                    "byte index 6 is not a char boundary; it is inside 'β' (bytes 5..7) of";

                !!generate_tests!!
            }

            mod rangeinclusive_1 {
                let DATA = super::DATA;

                let BAD_INPUT = super::BAD_START..=super::GOOD_END_INCL;
                const EXPECT_MSG =
                    "byte index 4 is not a char boundary; it is inside 'α' (bytes 3..5) of";

                !!generate_tests!!
            }

            mod rangeinclusive_2 {
                let DATA = super::DATA;

                let BAD_INPUT = super::GOOD_START..=super::BAD_END_INCL;
                const EXPECT_MSG =
                    "byte index 6 is not a char boundary; it is inside 'β' (bytes 5..7) of";

                !!generate_tests!!
            }

            mod rangetoinclusive {
                let DATA = super::DATA;

                let BAD_INPUT = ..=super::BAD_END_INCL;
                const EXPECT_MSG =
                    "byte index 6 is not a char boundary; it is inside 'β' (bytes 5..7) of";

                !!generate_tests!!
            }
        }
    }

    const LOREM_PARAGRAPH: &'static str = "\
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse quis lorem \
    sit amet dolor ultricies condimentum. Praesent iaculis purus elit, ac malesuada \
    quam malesuada in. Duis sed orci eros. Suspendisse sit amet magna mollis, mollis \
    nunc luctus, imperdiet mi. Integer fringilla non sem ut lacinia. Fusce varius \
    tortor a risus porttitor hendrerit. Morbi mauris dui, ultricies nec tempus vel, \
    gravida nec quam.";

    // check the panic includes the prefix of the sliced string
    #[test]
    #[should_panic(expected="byte index 1024 is out of bounds of `Lorem ipsum dolor sit amet")]
    fn test_slice_fail_truncated_1() {
        &LOREM_PARAGRAPH[..1024];
    }
    // check the truncation in the panic message
    #[test]
    #[should_panic(expected="luctus, im`[...]")]
    fn test_slice_fail_truncated_2() {
        &LOREM_PARAGRAPH[..1024];
    }
}

#[test]
fn test_str_slice_rangetoinclusive_ok() {
    let s = "abcαβγ";
    assert_eq!(&s[..=2], "abc");
    assert_eq!(&s[..=4], "abcα");
}

#[test]
#[should_panic]
fn test_str_slice_rangetoinclusive_notok() {
    let s = "abcαβγ";
    &s[..=3];
}

#[test]
fn test_str_slicemut_rangetoinclusive_ok() {
    let mut s = "abcαβγ".to_owned();
    let s: &mut str = &mut s;
    assert_eq!(&mut s[..=2], "abc");
    assert_eq!(&mut s[..=4], "abcα");
}

#[test]
#[should_panic]
fn test_str_slicemut_rangetoinclusive_notok() {
    let mut s = "abcαβγ".to_owned();
    let s: &mut str = &mut s;
    &mut s[..=3];
}

#[test]
fn test_is_char_boundary() {
    let s = "ศไทย中华Việt Nam β-release 🐱123";
    assert!(s.is_char_boundary(0));
    assert!(s.is_char_boundary(s.len()));
    assert!(!s.is_char_boundary(s.len() + 1));
    for (i, ch) in s.char_indices() {
        // ensure character locations are boundaries and continuation bytes are not
        assert!(s.is_char_boundary(i), "{} is a char boundary in {:?}", i, s);
        for j in 1..ch.len_utf8() {
            assert!(!s.is_char_boundary(i + j),
                    "{} should not be a char boundary in {:?}", i + j, s);
        }
    }
}

#[test]
fn test_trim_left_matches() {
    let v: &[char] = &[];
    assert_eq!(" *** foo *** ".trim_left_matches(v), " *** foo *** ");
    let chars: &[char] = &['*', ' '];
    assert_eq!(" *** foo *** ".trim_left_matches(chars), "foo *** ");
    assert_eq!(" ***  *** ".trim_left_matches(chars), "");
    assert_eq!("foo *** ".trim_left_matches(chars), "foo *** ");

    assert_eq!("11foo1bar11".trim_left_matches('1'), "foo1bar11");
    let chars: &[char] = &['1', '2'];
    assert_eq!("12foo1bar12".trim_left_matches(chars), "foo1bar12");
    assert_eq!("123foo1bar123".trim_left_matches(|c: char| c.is_numeric()), "foo1bar123");
}

#[test]
fn test_trim_right_matches() {
    let v: &[char] = &[];
    assert_eq!(" *** foo *** ".trim_right_matches(v), " *** foo *** ");
    let chars: &[char] = &['*', ' '];
    assert_eq!(" *** foo *** ".trim_right_matches(chars), " *** foo");
    assert_eq!(" ***  *** ".trim_right_matches(chars), "");
    assert_eq!(" *** foo".trim_right_matches(chars), " *** foo");

    assert_eq!("11foo1bar11".trim_right_matches('1'), "11foo1bar");
    let chars: &[char] = &['1', '2'];
    assert_eq!("12foo1bar12".trim_right_matches(chars), "12foo1bar");
    assert_eq!("123foo1bar123".trim_right_matches(|c: char| c.is_numeric()), "123foo1bar");
}

#[test]
fn test_trim_matches() {
    let v: &[char] = &[];
    assert_eq!(" *** foo *** ".trim_matches(v), " *** foo *** ");
    let chars: &[char] = &['*', ' '];
    assert_eq!(" *** foo *** ".trim_matches(chars), "foo");
    assert_eq!(" ***  *** ".trim_matches(chars), "");
    assert_eq!("foo".trim_matches(chars), "foo");

    assert_eq!("11foo1bar11".trim_matches('1'), "foo1bar");
    let chars: &[char] = &['1', '2'];
    assert_eq!("12foo1bar12".trim_matches(chars), "foo1bar");
    assert_eq!("123foo1bar123".trim_matches(|c: char| c.is_numeric()), "foo1bar");
}

#[test]
fn test_trim_left() {
    assert_eq!("".trim_left(), "");
    assert_eq!("a".trim_left(), "a");
    assert_eq!("    ".trim_left(), "");
    assert_eq!("     blah".trim_left(), "blah");
    assert_eq!("   \u{3000}  wut".trim_left(), "wut");
    assert_eq!("hey ".trim_left(), "hey ");
}

#[test]
fn test_trim_right() {
    assert_eq!("".trim_right(), "");
    assert_eq!("a".trim_right(), "a");
    assert_eq!("    ".trim_right(), "");
    assert_eq!("blah     ".trim_right(), "blah");
    assert_eq!("wut   \u{3000}  ".trim_right(), "wut");
    assert_eq!(" hey".trim_right(), " hey");
}

#[test]
fn test_trim() {
    assert_eq!("".trim(), "");
    assert_eq!("a".trim(), "a");
    assert_eq!("    ".trim(), "");
    assert_eq!("    blah     ".trim(), "blah");
    assert_eq!("\nwut   \u{3000}  ".trim(), "wut");
    assert_eq!(" hey dude ".trim(), "hey dude");
}

#[test]
fn test_is_whitespace() {
    assert!("".chars().all(|c| c.is_whitespace()));
    assert!(" ".chars().all(|c| c.is_whitespace()));
    assert!("\u{2009}".chars().all(|c| c.is_whitespace())); // Thin space
    assert!("  \n\t   ".chars().all(|c| c.is_whitespace()));
    assert!(!"   _   ".chars().all(|c| c.is_whitespace()));
}

#[test]
fn test_is_utf8() {
    // deny overlong encodings
    assert!(from_utf8(&[0xc0, 0x80]).is_err());
    assert!(from_utf8(&[0xc0, 0xae]).is_err());
    assert!(from_utf8(&[0xe0, 0x80, 0x80]).is_err());
    assert!(from_utf8(&[0xe0, 0x80, 0xaf]).is_err());
    assert!(from_utf8(&[0xe0, 0x81, 0x81]).is_err());
    assert!(from_utf8(&[0xf0, 0x82, 0x82, 0xac]).is_err());
    assert!(from_utf8(&[0xf4, 0x90, 0x80, 0x80]).is_err());

    // deny surrogates
    assert!(from_utf8(&[0xED, 0xA0, 0x80]).is_err());
    assert!(from_utf8(&[0xED, 0xBF, 0xBF]).is_err());

    assert!(from_utf8(&[0xC2, 0x80]).is_ok());
    assert!(from_utf8(&[0xDF, 0xBF]).is_ok());
    assert!(from_utf8(&[0xE0, 0xA0, 0x80]).is_ok());
    assert!(from_utf8(&[0xED, 0x9F, 0xBF]).is_ok());
    assert!(from_utf8(&[0xEE, 0x80, 0x80]).is_ok());
    assert!(from_utf8(&[0xEF, 0xBF, 0xBF]).is_ok());
    assert!(from_utf8(&[0xF0, 0x90, 0x80, 0x80]).is_ok());
    assert!(from_utf8(&[0xF4, 0x8F, 0xBF, 0xBF]).is_ok());
}

#[test]
fn from_utf8_mostly_ascii() {
    // deny invalid bytes embedded in long stretches of ascii
    for i in 32..64 {
        let mut data = [0; 128];
        data[i] = 0xC0;
        assert!(from_utf8(&data).is_err());
        data[i] = 0xC2;
        assert!(from_utf8(&data).is_err());
    }
}

#[test]
fn from_utf8_error() {
    macro_rules! test {
        ($input: expr, $expected_valid_up_to: expr, $expected_error_len: expr) => {
            let error = from_utf8($input).unwrap_err();
            assert_eq!(error.valid_up_to(), $expected_valid_up_to);
            assert_eq!(error.error_len(), $expected_error_len);
        }
    }
    test!(b"A\xC3\xA9 \xFF ", 4, Some(1));
    test!(b"A\xC3\xA9 \x80 ", 4, Some(1));
    test!(b"A\xC3\xA9 \xC1 ", 4, Some(1));
    test!(b"A\xC3\xA9 \xC1", 4, Some(1));
    test!(b"A\xC3\xA9 \xC2", 4, None);
    test!(b"A\xC3\xA9 \xC2 ", 4, Some(1));
    test!(b"A\xC3\xA9 \xC2\xC0", 4, Some(1));
    test!(b"A\xC3\xA9 \xE0", 4, None);
    test!(b"A\xC3\xA9 \xE0\x9F", 4, Some(1));
    test!(b"A\xC3\xA9 \xE0\xA0", 4, None);
    test!(b"A\xC3\xA9 \xE0\xA0\xC0", 4, Some(2));
    test!(b"A\xC3\xA9 \xE0\xA0 ", 4, Some(2));
    test!(b"A\xC3\xA9 \xED\xA0\x80 ", 4, Some(1));
    test!(b"A\xC3\xA9 \xF1", 4, None);
    test!(b"A\xC3\xA9 \xF1\x80", 4, None);
    test!(b"A\xC3\xA9 \xF1\x80\x80", 4, None);
    test!(b"A\xC3\xA9 \xF1 ", 4, Some(1));
    test!(b"A\xC3\xA9 \xF1\x80 ", 4, Some(2));
    test!(b"A\xC3\xA9 \xF1\x80\x80 ", 4, Some(3));
}

#[test]
fn test_as_bytes() {
    // no null
    let v = [
        224, 184, 168, 224, 185, 132, 224, 184, 151, 224, 184, 162, 228,
        184, 173, 229, 141, 142, 86, 105, 225, 187, 135, 116, 32, 78, 97,
        109
    ];
    let b: &[u8] = &[];
    assert_eq!("".as_bytes(), b);
    assert_eq!("abc".as_bytes(), b"abc");
    assert_eq!("ศไทย中华Việt Nam".as_bytes(), v);
}

#[test]
#[should_panic]
fn test_as_bytes_fail() {
    // Don't double free. (I'm not sure if this exercises the
    // original problem code path anymore.)
    let s = String::from("");
    let _bytes = s.as_bytes();
    panic!();
}

#[test]
fn test_as_ptr() {
    let buf = "hello".as_ptr();
    unsafe {
        assert_eq!(*buf.offset(0), b'h');
        assert_eq!(*buf.offset(1), b'e');
        assert_eq!(*buf.offset(2), b'l');
        assert_eq!(*buf.offset(3), b'l');
        assert_eq!(*buf.offset(4), b'o');
    }
}

#[test]
fn vec_str_conversions() {
    let s1: String = String::from("All mimsy were the borogoves");

    let v: Vec<u8> = s1.as_bytes().to_vec();
    let s2: String = String::from(from_utf8(&v).unwrap());
    let mut i = 0;
    let n1 = s1.len();
    let n2 = v.len();
    assert_eq!(n1, n2);
    while i < n1 {
        let a: u8 = s1.as_bytes()[i];
        let b: u8 = s2.as_bytes()[i];
        assert_eq!(a, b);
        i += 1;
    }
}

#[test]
fn test_contains() {
    assert!("abcde".contains("bcd"));
    assert!("abcde".contains("abcd"));
    assert!("abcde".contains("bcde"));
    assert!("abcde".contains(""));
    assert!("".contains(""));
    assert!(!"abcde".contains("def"));
    assert!(!"".contains("a"));

    let data = "ประเทศไทย中华Việt Nam";
    assert!(data.contains("ประเ"));
    assert!(data.contains("ะเ"));
    assert!(data.contains("中华"));
    assert!(!data.contains("ไท华"));
}

#[test]
fn test_contains_char() {
    assert!("abc".contains('b'));
    assert!("a".contains('a'));
    assert!(!"abc".contains('d'));
    assert!(!"".contains('a'));
}

#[test]
fn test_split_at() {
    let s = "ศไทย中华Việt Nam";
    for (index, _) in s.char_indices() {
        let (a, b) = s.split_at(index);
        assert_eq!(&s[..a.len()], a);
        assert_eq!(&s[a.len()..], b);
    }
    let (a, b) = s.split_at(s.len());
    assert_eq!(a, s);
    assert_eq!(b, "");
}

#[test]
fn test_split_at_mut() {
    let mut s = "Hello World".to_string();
    {
        let (a, b) = s.split_at_mut(5);
        a.make_ascii_uppercase();
        b.make_ascii_lowercase();
    }
    assert_eq!(s, "HELLO world");
}

#[test]
#[should_panic]
fn test_split_at_boundscheck() {
    let s = "ศไทย中华Việt Nam";
    s.split_at(1);
}

#[test]
fn test_escape_unicode() {
    assert_eq!("abc".escape_unicode(), "\\u{61}\\u{62}\\u{63}");
    assert_eq!("a c".escape_unicode(), "\\u{61}\\u{20}\\u{63}");
    assert_eq!("\r\n\t".escape_unicode(), "\\u{d}\\u{a}\\u{9}");
    assert_eq!("'\"\\".escape_unicode(), "\\u{27}\\u{22}\\u{5c}");
    assert_eq!("\x00\x01\u{fe}\u{ff}".escape_unicode(), "\\u{0}\\u{1}\\u{fe}\\u{ff}");
    assert_eq!("\u{100}\u{ffff}".escape_unicode(), "\\u{100}\\u{ffff}");
    assert_eq!("\u{10000}\u{10ffff}".escape_unicode(), "\\u{10000}\\u{10ffff}");
    assert_eq!("ab\u{fb00}".escape_unicode(), "\\u{61}\\u{62}\\u{fb00}");
    assert_eq!("\u{1d4ea}\r".escape_unicode(), "\\u{1d4ea}\\u{d}");
}

#[test]
fn test_escape_debug() {
    assert_eq!("abc".escape_debug(), "abc");
    assert_eq!("a c".escape_debug(), "a c");
    assert_eq!("éèê".escape_debug(), "éèê");
    assert_eq!("\r\n\t".escape_debug(), "\\r\\n\\t");
    assert_eq!("'\"\\".escape_debug(), "\\'\\\"\\\\");
    assert_eq!("\u{7f}\u{ff}".escape_debug(), "\\u{7f}\u{ff}");
    assert_eq!("\u{100}\u{ffff}".escape_debug(), "\u{100}\\u{ffff}");
    assert_eq!("\u{10000}\u{10ffff}".escape_debug(), "\u{10000}\\u{10ffff}");
    assert_eq!("ab\u{200b}".escape_debug(), "ab\\u{200b}");
    assert_eq!("\u{10d4ea}\r".escape_debug(), "\\u{10d4ea}\\r");
}

#[test]
fn test_escape_default() {
    assert_eq!("abc".escape_default(), "abc");
    assert_eq!("a c".escape_default(), "a c");
    assert_eq!("éèê".escape_default(), "\\u{e9}\\u{e8}\\u{ea}");
    assert_eq!("\r\n\t".escape_default(), "\\r\\n\\t");
    assert_eq!("'\"\\".escape_default(), "\\'\\\"\\\\");
    assert_eq!("\u{7f}\u{ff}".escape_default(), "\\u{7f}\\u{ff}");
    assert_eq!("\u{100}\u{ffff}".escape_default(), "\\u{100}\\u{ffff}");
    assert_eq!("\u{10000}\u{10ffff}".escape_default(), "\\u{10000}\\u{10ffff}");
    assert_eq!("ab\u{200b}".escape_default(), "ab\\u{200b}");
    assert_eq!("\u{10d4ea}\r".escape_default(), "\\u{10d4ea}\\r");
}

#[test]
fn test_total_ord() {
    assert_eq!("1234".cmp("123"), Greater);
    assert_eq!("123".cmp("1234"), Less);
    assert_eq!("1234".cmp("1234"), Equal);
    assert_eq!("12345555".cmp("123456"), Less);
    assert_eq!("22".cmp("1234"), Greater);
}

#[test]
fn test_iterator() {
    let s = "ศไทย中华Việt Nam";
    let v = ['ศ','ไ','ท','ย','中','华','V','i','ệ','t',' ','N','a','m'];

    let mut pos = 0;
    let it = s.chars();

    for c in it {
        assert_eq!(c, v[pos]);
        pos += 1;
    }
    assert_eq!(pos, v.len());
    assert_eq!(s.chars().count(), v.len());
}

#[test]
fn test_rev_iterator() {
    let s = "ศไทย中华Việt Nam";
    let v = ['m', 'a', 'N', ' ', 't', 'ệ','i','V','华','中','ย','ท','ไ','ศ'];

    let mut pos = 0;
    let it = s.chars().rev();

    for c in it {
        assert_eq!(c, v[pos]);
        pos += 1;
    }
    assert_eq!(pos, v.len());
}

#[test]
fn test_chars_decoding() {
    let mut bytes = [0; 4];
    for c in (0..0x110000).filter_map(::std::char::from_u32) {
        let s = c.encode_utf8(&mut bytes);
        if Some(c) != s.chars().next() {
            panic!("character {:x}={} does not decode correctly", c as u32, c);
        }
    }
}

#[test]
fn test_chars_rev_decoding() {
    let mut bytes = [0; 4];
    for c in (0..0x110000).filter_map(::std::char::from_u32) {
        let s = c.encode_utf8(&mut bytes);
        if Some(c) != s.chars().rev().next() {
            panic!("character {:x}={} does not decode correctly", c as u32, c);
        }
    }
}

#[test]
fn test_iterator_clone() {
    let s = "ศไทย中华Việt Nam";
    let mut it = s.chars();
    it.next();
    assert!(it.clone().zip(it).all(|(x,y)| x == y));
}

#[test]
fn test_iterator_last() {
    let s = "ศไทย中华Việt Nam";
    let mut it = s.chars();
    it.next();
    assert_eq!(it.last(), Some('m'));
}

#[test]
fn test_bytesator() {
    let s = "ศไทย中华Việt Nam";
    let v = [
        224, 184, 168, 224, 185, 132, 224, 184, 151, 224, 184, 162, 228,
        184, 173, 229, 141, 142, 86, 105, 225, 187, 135, 116, 32, 78, 97,
        109
    ];
    let mut pos = 0;

    for b in s.bytes() {
        assert_eq!(b, v[pos]);
        pos += 1;
    }
}

#[test]
fn test_bytes_revator() {
    let s = "ศไทย中华Việt Nam";
    let v = [
        224, 184, 168, 224, 185, 132, 224, 184, 151, 224, 184, 162, 228,
        184, 173, 229, 141, 142, 86, 105, 225, 187, 135, 116, 32, 78, 97,
        109
    ];
    let mut pos = v.len();

    for b in s.bytes().rev() {
        pos -= 1;
        assert_eq!(b, v[pos]);
    }
}

#[test]
fn test_bytesator_nth() {
    let s = "ศไทย中华Việt Nam";
    let v = [
        224, 184, 168, 224, 185, 132, 224, 184, 151, 224, 184, 162, 228,
        184, 173, 229, 141, 142, 86, 105, 225, 187, 135, 116, 32, 78, 97,
        109
    ];

    let mut b = s.bytes();
    assert_eq!(b.nth(2).unwrap(), v[2]);
    assert_eq!(b.nth(10).unwrap(), v[10]);
    assert_eq!(b.nth(200), None);
}

#[test]
fn test_bytesator_count() {
    let s = "ศไทย中华Việt Nam";

    let b = s.bytes();
    assert_eq!(b.count(), 28)
}

#[test]
fn test_bytesator_last() {
    let s = "ศไทย中华Việt Nam";

    let b = s.bytes();
    assert_eq!(b.last().unwrap(), 109)
}

#[test]
fn test_char_indicesator() {
    let s = "ศไทย中华Việt Nam";
    let p = [0, 3, 6, 9, 12, 15, 18, 19, 20, 23, 24, 25, 26, 27];
    let v = ['ศ','ไ','ท','ย','中','华','V','i','ệ','t',' ','N','a','m'];

    let mut pos = 0;
    let it = s.char_indices();

    for c in it {
        assert_eq!(c, (p[pos], v[pos]));
        pos += 1;
    }
    assert_eq!(pos, v.len());
    assert_eq!(pos, p.len());
}

#[test]
fn test_char_indices_revator() {
    let s = "ศไทย中华Việt Nam";
    let p = [27, 26, 25, 24, 23, 20, 19, 18, 15, 12, 9, 6, 3, 0];
    let v = ['m', 'a', 'N', ' ', 't', 'ệ','i','V','华','中','ย','ท','ไ','ศ'];

    let mut pos = 0;
    let it = s.char_indices().rev();

    for c in it {
        assert_eq!(c, (p[pos], v[pos]));
        pos += 1;
    }
    assert_eq!(pos, v.len());
    assert_eq!(pos, p.len());
}

#[test]
fn test_char_indices_last() {
    let s = "ศไทย中华Việt Nam";
    let mut it = s.char_indices();
    it.next();
    assert_eq!(it.last(), Some((27, 'm')));
}

#[test]
fn test_splitn_char_iterator() {
    let data = "\nMäry häd ä little lämb\nLittle lämb\n";

    let split: Vec<&str> = data.splitn(4, ' ').collect();
    assert_eq!(split, ["\nMäry", "häd", "ä", "little lämb\nLittle lämb\n"]);

    let split: Vec<&str> = data.splitn(4, |c: char| c == ' ').collect();
    assert_eq!(split, ["\nMäry", "häd", "ä", "little lämb\nLittle lämb\n"]);

    // Unicode
    let split: Vec<&str> = data.splitn(4, 'ä').collect();
    assert_eq!(split, ["\nM", "ry h", "d ", " little lämb\nLittle lämb\n"]);

    let split: Vec<&str> = data.splitn(4, |c: char| c == 'ä').collect();
    assert_eq!(split, ["\nM", "ry h", "d ", " little lämb\nLittle lämb\n"]);
}

#[test]
fn test_split_char_iterator_no_trailing() {
    let data = "\nMäry häd ä little lämb\nLittle lämb\n";

    let split: Vec<&str> = data.split('\n').collect();
    assert_eq!(split, ["", "Märy häd ä little lämb", "Little lämb", ""]);

    let split: Vec<&str> = data.split_terminator('\n').collect();
    assert_eq!(split, ["", "Märy häd ä little lämb", "Little lämb"]);
}

#[test]
fn test_rsplit() {
    let data = "\nMäry häd ä little lämb\nLittle lämb\n";

    let split: Vec<&str> = data.rsplit(' ').collect();
    assert_eq!(split, ["lämb\n", "lämb\nLittle", "little", "ä", "häd", "\nMäry"]);

    let split: Vec<&str> = data.rsplit("lämb").collect();
    assert_eq!(split, ["\n", "\nLittle ", "\nMäry häd ä little "]);

    let split: Vec<&str> = data.rsplit(|c: char| c == 'ä').collect();
    assert_eq!(split, ["mb\n", "mb\nLittle l", " little l", "d ", "ry h", "\nM"]);
}

#[test]
fn test_rsplitn() {
    let data = "\nMäry häd ä little lämb\nLittle lämb\n";

    let split: Vec<&str> = data.rsplitn(2, ' ').collect();
    assert_eq!(split, ["lämb\n", "\nMäry häd ä little lämb\nLittle"]);

    let split: Vec<&str> = data.rsplitn(2, "lämb").collect();
    assert_eq!(split, ["\n", "\nMäry häd ä little lämb\nLittle "]);

    let split: Vec<&str> = data.rsplitn(2, |c: char| c == 'ä').collect();
    assert_eq!(split, ["mb\n", "\nMäry häd ä little lämb\nLittle l"]);
}

#[test]
fn test_split_whitespace() {
    let data = "\n \tMäry   häd\tä  little lämb\nLittle lämb\n";
    let words: Vec<&str> = data.split_whitespace().collect();
    assert_eq!(words, ["Märy", "häd", "ä", "little", "lämb", "Little", "lämb"])
}

#[test]
fn test_lines() {
    let data = "\nMäry häd ä little lämb\n\r\nLittle lämb\n";
    let lines: Vec<&str> = data.lines().collect();
    assert_eq!(lines, ["", "Märy häd ä little lämb", "", "Little lämb"]);

    let data = "\r\nMäry häd ä little lämb\n\nLittle lämb"; // no trailing \n
    let lines: Vec<&str> = data.lines().collect();
    assert_eq!(lines, ["", "Märy häd ä little lämb", "", "Little lämb"]);
}

#[test]
fn test_splitator() {
    fn t(s: &str, sep: &str, u: &[&str]) {
        let v: Vec<&str> = s.split(sep).collect();
        assert_eq!(v, u);
    }
    t("--1233345--", "12345", &["--1233345--"]);
    t("abc::hello::there", "::", &["abc", "hello", "there"]);
    t("::hello::there", "::", &["", "hello", "there"]);
    t("hello::there::", "::", &["hello", "there", ""]);
    t("::hello::there::", "::", &["", "hello", "there", ""]);
    t("ประเทศไทย中华Việt Nam", "中华", &["ประเทศไทย", "Việt Nam"]);
    t("zzXXXzzYYYzz", "zz", &["", "XXX", "YYY", ""]);
    t("zzXXXzYYYz", "XXX", &["zz", "zYYYz"]);
    t(".XXX.YYY.", ".", &["", "XXX", "YYY", ""]);
    t("", ".", &[""]);
    t("zz", "zz", &["",""]);
    t("ok", "z", &["ok"]);
    t("zzz", "zz", &["","z"]);
    t("zzzzz", "zz", &["","","z"]);
}

#[test]
fn test_str_default() {
    use std::default::Default;

    fn t<S: Default + AsRef<str>>() {
        let s: S = Default::default();
        assert_eq!(s.as_ref(), "");
    }

    t::<&str>();
    t::<String>();
}

#[test]
fn test_str_container() {
    fn sum_len(v: &[&str]) -> usize {
        v.iter().map(|x| x.len()).sum()
    }

    let s = "01234";
    assert_eq!(5, sum_len(&["012", "", "34"]));
    assert_eq!(5, sum_len(&["01", "2", "34", ""]));
    assert_eq!(5, sum_len(&[s]));
}

#[test]
fn test_str_from_utf8() {
    let xs = b"hello";
    assert_eq!(from_utf8(xs), Ok("hello"));

    let xs = "ศไทย中华Việt Nam".as_bytes();
    assert_eq!(from_utf8(xs), Ok("ศไทย中华Việt Nam"));

    let xs = b"hello\xFF";
    assert!(from_utf8(xs).is_err());
}

#[test]
fn test_pattern_deref_forward() {
    let data = "aabcdaa";
    assert!(data.contains("bcd"));
    assert!(data.contains(&"bcd"));
    assert!(data.contains(&"bcd".to_string()));
}

#[test]
fn test_empty_match_indices() {
    let data = "aä中!";
    let vec: Vec<_> = data.match_indices("").collect();
    assert_eq!(vec, [(0, ""), (1, ""), (3, ""), (6, ""), (7, "")]);
}

#[test]
fn test_bool_from_str() {
    assert_eq!("true".parse().ok(), Some(true));
    assert_eq!("false".parse().ok(), Some(false));
    assert_eq!("not even a boolean".parse::<bool>().ok(), None);
}

fn check_contains_all_substrings(s: &str) {
    assert!(s.contains(""));
    for i in 0..s.len() {
        for j in i+1..s.len() + 1 {
            assert!(s.contains(&s[i..j]));
        }
    }
}

#[test]
fn strslice_issue_16589() {
    assert!("bananas".contains("nana"));

    // prior to the fix for #16589, x.contains("abcdabcd") returned false
    // test all substrings for good measure
    check_contains_all_substrings("012345678901234567890123456789bcdabcdabcd");
}

#[test]
fn strslice_issue_16878() {
    assert!(!"1234567ah012345678901ah".contains("hah"));
    assert!(!"00abc01234567890123456789abc".contains("bcabc"));
}


#[test]
fn test_strslice_contains() {
    let x = "There are moments, Jeeves, when one asks oneself, 'Do trousers matter?'";
    check_contains_all_substrings(x);
}

#[test]
fn test_rsplitn_char_iterator() {
    let data = "\nMäry häd ä little lämb\nLittle lämb\n";

    let mut split: Vec<&str> = data.rsplitn(4, ' ').collect();
    split.reverse();
    assert_eq!(split, ["\nMäry häd ä", "little", "lämb\nLittle", "lämb\n"]);

    let mut split: Vec<&str> = data.rsplitn(4, |c: char| c == ' ').collect();
    split.reverse();
    assert_eq!(split, ["\nMäry häd ä", "little", "lämb\nLittle", "lämb\n"]);

    // Unicode
    let mut split: Vec<&str> = data.rsplitn(4, 'ä').collect();
    split.reverse();
    assert_eq!(split, ["\nMäry häd ", " little l", "mb\nLittle l", "mb\n"]);

    let mut split: Vec<&str> = data.rsplitn(4, |c: char| c == 'ä').collect();
    split.reverse();
    assert_eq!(split, ["\nMäry häd ", " little l", "mb\nLittle l", "mb\n"]);
}

#[test]
fn test_split_char_iterator() {
    let data = "\nMäry häd ä little lämb\nLittle lämb\n";

    let split: Vec<&str> = data.split(' ').collect();
    assert_eq!( split, ["\nMäry", "häd", "ä", "little", "lämb\nLittle", "lämb\n"]);

    let mut rsplit: Vec<&str> = data.split(' ').rev().collect();
    rsplit.reverse();
    assert_eq!(rsplit, ["\nMäry", "häd", "ä", "little", "lämb\nLittle", "lämb\n"]);

    let split: Vec<&str> = data.split(|c: char| c == ' ').collect();
    assert_eq!( split, ["\nMäry", "häd", "ä", "little", "lämb\nLittle", "lämb\n"]);

    let mut rsplit: Vec<&str> = data.split(|c: char| c == ' ').rev().collect();
    rsplit.reverse();
    assert_eq!(rsplit, ["\nMäry", "häd", "ä", "little", "lämb\nLittle", "lämb\n"]);

    // Unicode
    let split: Vec<&str> = data.split('ä').collect();
    assert_eq!( split, ["\nM", "ry h", "d ", " little l", "mb\nLittle l", "mb\n"]);

    let mut rsplit: Vec<&str> = data.split('ä').rev().collect();
    rsplit.reverse();
    assert_eq!(rsplit, ["\nM", "ry h", "d ", " little l", "mb\nLittle l", "mb\n"]);

    let split: Vec<&str> = data.split(|c: char| c == 'ä').collect();
    assert_eq!( split, ["\nM", "ry h", "d ", " little l", "mb\nLittle l", "mb\n"]);

    let mut rsplit: Vec<&str> = data.split(|c: char| c == 'ä').rev().collect();
    rsplit.reverse();
    assert_eq!(rsplit, ["\nM", "ry h", "d ", " little l", "mb\nLittle l", "mb\n"]);
}

#[test]
fn test_rev_split_char_iterator_no_trailing() {
    let data = "\nMäry häd ä little lämb\nLittle lämb\n";

    let mut split: Vec<&str> = data.split('\n').rev().collect();
    split.reverse();
    assert_eq!(split, ["", "Märy häd ä little lämb", "Little lämb", ""]);

    let mut split: Vec<&str> = data.split_terminator('\n').rev().collect();
    split.reverse();
    assert_eq!(split, ["", "Märy häd ä little lämb", "Little lämb"]);
}

#[test]
fn test_utf16_code_units() {
    assert_eq!("é\u{1F4A9}".encode_utf16().collect::<Vec<u16>>(),
               [0xE9, 0xD83D, 0xDCA9])
}

#[test]
fn starts_with_in_unicode() {
    assert!(!"├── Cargo.toml".starts_with("# "));
}

#[test]
fn starts_short_long() {
    assert!(!"".starts_with("##"));
    assert!(!"##".starts_with("####"));
    assert!("####".starts_with("##"));
    assert!(!"##ä".starts_with("####"));
    assert!("####ä".starts_with("##"));
    assert!(!"##".starts_with("####ä"));
    assert!("##ä##".starts_with("##ä"));

    assert!("".starts_with(""));
    assert!("ä".starts_with(""));
    assert!("#ä".starts_with(""));
    assert!("##ä".starts_with(""));
    assert!("ä###".starts_with(""));
    assert!("#ä##".starts_with(""));
    assert!("##ä#".starts_with(""));
}

#[test]
fn contains_weird_cases() {
    assert!("* \t".contains(' '));
    assert!(!"* \t".contains('?'));
    assert!(!"* \t".contains('\u{1F4A9}'));
}

#[test]
fn trim_ws() {
    assert_eq!(" \t  a \t  ".trim_left_matches(|c: char| c.is_whitespace()),
                    "a \t  ");
    assert_eq!(" \t  a \t  ".trim_right_matches(|c: char| c.is_whitespace()),
               " \t  a");
    assert_eq!(" \t  a \t  ".trim_matches(|c: char| c.is_whitespace()),
                    "a");
    assert_eq!(" \t   \t  ".trim_left_matches(|c: char| c.is_whitespace()),
                         "");
    assert_eq!(" \t   \t  ".trim_right_matches(|c: char| c.is_whitespace()),
               "");
    assert_eq!(" \t   \t  ".trim_matches(|c: char| c.is_whitespace()),
               "");
}

#[test]
fn to_lowercase() {
    assert_eq!("".to_lowercase(), "");
    assert_eq!("AÉDžaé ".to_lowercase(), "aédžaé ");

    // https://github.com/rust-lang/rust/issues/26035
    assert_eq!("ΑΣ".to_lowercase(), "ας");
    assert_eq!("Α'Σ".to_lowercase(), "α'ς");
    assert_eq!("Α''Σ".to_lowercase(), "α''ς");

    assert_eq!("ΑΣ Α".to_lowercase(), "ας α");
    assert_eq!("Α'Σ Α".to_lowercase(), "α'ς α");
    assert_eq!("Α''Σ Α".to_lowercase(), "α''ς α");

    assert_eq!("ΑΣ' Α".to_lowercase(), "ας' α");
    assert_eq!("ΑΣ'' Α".to_lowercase(), "ας'' α");

    assert_eq!("Α'Σ' Α".to_lowercase(), "α'ς' α");
    assert_eq!("Α''Σ'' Α".to_lowercase(), "α''ς'' α");

    assert_eq!("Α Σ".to_lowercase(), "α σ");
    assert_eq!("Α 'Σ".to_lowercase(), "α 'σ");
    assert_eq!("Α ''Σ".to_lowercase(), "α ''σ");

    assert_eq!("Σ".to_lowercase(), "σ");
    assert_eq!("'Σ".to_lowercase(), "'σ");
    assert_eq!("''Σ".to_lowercase(), "''σ");

    assert_eq!("ΑΣΑ".to_lowercase(), "ασα");
    assert_eq!("ΑΣ'Α".to_lowercase(), "ασ'α");
    assert_eq!("ΑΣ''Α".to_lowercase(), "ασ''α");
}

#[test]
fn to_uppercase() {
    assert_eq!("".to_uppercase(), "");
    assert_eq!("aéDžßfiᾀ".to_uppercase(), "AÉDŽSSFIἈΙ");
}

#[test]
fn test_into_string() {
    // The only way to acquire a Box<str> in the first place is through a String, so just
    // test that we can round-trip between Box<str> and String.
    let string = String::from("Some text goes here");
    assert_eq!(string.clone().into_boxed_str().into_string(), string);
}

#[test]
fn test_box_slice_clone() {
    let data = String::from("hello HELLO hello HELLO yes YES 5 中ä华!!!");
    let data2 = data.clone().into_boxed_str().clone().into_string();

    assert_eq!(data, data2);
}

#[test]
fn test_cow_from() {
    let borrowed = "borrowed";
    let owned = String::from("owned");
    match (Cow::from(owned.clone()), Cow::from(borrowed)) {
        (Cow::Owned(o), Cow::Borrowed(b)) => assert!(o == owned && b == borrowed),
        _ => panic!("invalid `Cow::from`"),
    }
}

#[test]
fn test_repeat() {
    assert_eq!("".repeat(3), "");
    assert_eq!("abc".repeat(0), "");
    assert_eq!("α".repeat(3), "ααα");
}

mod pattern {
    use std::str::pattern::Pattern;
    use std::str::pattern::{Searcher, ReverseSearcher};
    use std::str::pattern::SearchStep::{self, Match, Reject, Done};

    macro_rules! make_test {
        ($name:ident, $p:expr, $h:expr, [$($e:expr,)*]) => {
            #[allow(unused_imports)]
            mod $name {
                use std::str::pattern::SearchStep::{Match, Reject};
                use super::{cmp_search_to_vec};
                #[test]
                fn fwd() {
                    cmp_search_to_vec(false, $p, $h, vec![$($e),*]);
                }
                #[test]
                fn bwd() {
                    cmp_search_to_vec(true, $p, $h, vec![$($e),*]);
                }
            }
        }
    }

    fn cmp_search_to_vec<'a, P: Pattern<'a>>(rev: bool, pat: P, haystack: &'a str,
                                             right: Vec<SearchStep>)
    where P::Searcher: ReverseSearcher<'a>
    {
        let mut searcher = pat.into_searcher(haystack);
        let mut v = vec![];
        loop {
            match if !rev {searcher.next()} else {searcher.next_back()} {
                Match(a, b) => v.push(Match(a, b)),
                Reject(a, b) => v.push(Reject(a, b)),
                Done => break,
            }
        }
        if rev {
            v.reverse();
        }

        let mut first_index = 0;
        let mut err = None;

        for (i, e) in right.iter().enumerate() {
            match *e {
                Match(a, b) | Reject(a, b)
                if a <= b && a == first_index => {
                    first_index = b;
                }
                _ => {
                    err = Some(i);
                    break;
                }
            }
        }

        if let Some(err) = err {
            panic!("Input skipped range at {}", err);
        }

        if first_index != haystack.len() {
            panic!("Did not cover whole input");
        }

        assert_eq!(v, right);
    }

    make_test!(str_searcher_ascii_haystack, "bb", "abbcbbd", [
        Reject(0, 1),
        Match (1, 3),
        Reject(3, 4),
        Match (4, 6),
        Reject(6, 7),
    ]);
    make_test!(str_searcher_ascii_haystack_seq, "bb", "abbcbbbbd", [
        Reject(0, 1),
        Match (1, 3),
        Reject(3, 4),
        Match (4, 6),
        Match (6, 8),
        Reject(8, 9),
    ]);
    make_test!(str_searcher_empty_needle_ascii_haystack, "", "abbcbbd", [
        Match (0, 0),
        Reject(0, 1),
        Match (1, 1),
        Reject(1, 2),
        Match (2, 2),
        Reject(2, 3),
        Match (3, 3),
        Reject(3, 4),
        Match (4, 4),
        Reject(4, 5),
        Match (5, 5),
        Reject(5, 6),
        Match (6, 6),
        Reject(6, 7),
        Match (7, 7),
    ]);
    make_test!(str_searcher_multibyte_haystack, " ", "├──", [
        Reject(0, 3),
        Reject(3, 6),
        Reject(6, 9),
    ]);
    make_test!(str_searcher_empty_needle_multibyte_haystack, "", "├──", [
        Match (0, 0),
        Reject(0, 3),
        Match (3, 3),
        Reject(3, 6),
        Match (6, 6),
        Reject(6, 9),
        Match (9, 9),
    ]);
    make_test!(str_searcher_empty_needle_empty_haystack, "", "", [
        Match(0, 0),
    ]);
    make_test!(str_searcher_nonempty_needle_empty_haystack, "├", "", [
    ]);
    make_test!(char_searcher_ascii_haystack, 'b', "abbcbbd", [
        Reject(0, 1),
        Match (1, 2),
        Match (2, 3),
        Reject(3, 4),
        Match (4, 5),
        Match (5, 6),
        Reject(6, 7),
    ]);
    make_test!(char_searcher_multibyte_haystack, ' ', "├──", [
        Reject(0, 3),
        Reject(3, 6),
        Reject(6, 9),
    ]);
    make_test!(char_searcher_short_haystack, '\u{1F4A9}', "* \t", [
        Reject(0, 1),
        Reject(1, 2),
        Reject(2, 3),
    ]);

}

macro_rules! generate_iterator_test {
    {
        $name:ident {
            $(
                ($($arg:expr),*) -> [$($t:tt)*];
            )*
        }
        with $fwd:expr, $bwd:expr;
    } => {
        #[test]
        fn $name() {
            $(
                {
                    let res = vec![$($t)*];

                    let fwd_vec: Vec<_> = ($fwd)($($arg),*).collect();
                    assert_eq!(fwd_vec, res);

                    let mut bwd_vec: Vec<_> = ($bwd)($($arg),*).collect();
                    bwd_vec.reverse();
                    assert_eq!(bwd_vec, res);
                }
            )*
        }
    };
    {
        $name:ident {
            $(
                ($($arg:expr),*) -> [$($t:tt)*];
            )*
        }
        with $fwd:expr;
    } => {
        #[test]
        fn $name() {
            $(
                {
                    let res = vec![$($t)*];

                    let fwd_vec: Vec<_> = ($fwd)($($arg),*).collect();
                    assert_eq!(fwd_vec, res);
                }
            )*
        }
    }
}

generate_iterator_test! {
    double_ended_split {
        ("foo.bar.baz", '.') -> ["foo", "bar", "baz"];
        ("foo::bar::baz", "::") -> ["foo", "bar", "baz"];
    }
    with str::split, str::rsplit;
}

generate_iterator_test! {
    double_ended_split_terminator {
        ("foo;bar;baz;", ';') -> ["foo", "bar", "baz"];
    }
    with str::split_terminator, str::rsplit_terminator;
}

generate_iterator_test! {
    double_ended_matches {
        ("a1b2c3", char::is_numeric) -> ["1", "2", "3"];
    }
    with str::matches, str::rmatches;
}

generate_iterator_test! {
    double_ended_match_indices {
        ("a1b2c3", char::is_numeric) -> [(1, "1"), (3, "2"), (5, "3")];
    }
    with str::match_indices, str::rmatch_indices;
}

generate_iterator_test! {
    not_double_ended_splitn {
        ("foo::bar::baz", 2, "::") -> ["foo", "bar::baz"];
    }
    with str::splitn;
}

generate_iterator_test! {
    not_double_ended_rsplitn {
        ("foo::bar::baz", 2, "::") -> ["baz", "foo::bar"];
    }
    with str::rsplitn;
}

#[test]
fn different_str_pattern_forwarding_lifetimes() {
    use std::str::pattern::Pattern;

    fn foo<'a, P>(p: P) where for<'b> &'b P: Pattern<'a> {
        for _ in 0..3 {
            "asdf".find(&p);
        }
    }

    foo::<&str>("x");
}